The present invention relates to enclosures for electronic devices, and more particularly to enclosures having one or more hollow, cylindrical body portions with a header on one or both ends used in cable television (CATV) applications.
Coaxial cable devices such as RF filters mounted upon circuit boards are commonly housed in cylindrical enclosures having so-called body and header portions. When the device is installed in the field, the installer typically used a wrench to connect and tighten the adjoining connector, thereby applying a torque to the header. This torque is often great enough to cause rotation of the header relative to the body, resulting in failure of the device. Prior attempts to address this problem have included providing flat (i.e., linear) sides on the otherwise circular header which mate with flat sides on the interior of one end of an outer sleeve surrounding both the body and header. Such arrangements, although they may rotationally lock the header and outer sleeve, do not ensure that the header and body will not rotate relative to one another.
Of course, it is necessary that the body and header of such devices be permanently assembled in a manner which prevents longitudinal separation of the parts. This feature is commonly provided in current designs by an inductive soldering operation having a number of drawbacks not the least of which is the requirement to purchase and maintain the inductive soldering equipment. This equipment is added to multiple pieces of automated assembly equipment to control all aspects of the soldering process which is extremely critical to function or failure of the device. The many uncontrollable variables make the soldering process very unstable, resulting in high maintenance cost as well as higher scrap rates. Some of these variables are induction coil diameter, coil spacing between the wrapped coils, power connection channels, temperature of product/process areas and cooling system efficiency. Furthermore, spare parts must be stocked for the soldering equipment, creating an additional expense, as does the power required to operate the equipment. Consequently, significant savings could be realized by elimination of the induction soldering operation.
The principal object of the present invention is to provide an electronic device for the CATV industry having novel and improved means for maintaining a cylindrical body in assembled relation with a header.
Another object is to provide an electronic device including a housing formed by a hollow cylindrical body with a header at one or both ends wherein torque may be applied to the device without relative rotation of the body and header.
A further object is to provide means for preventing relative rotation of header and body portions of an electronic device in response to torque applied to the device during installation in the field.
It is also an object of the invention to provide means for longitudinal locking of body and header portions of an electronic device without requiring any soldering operation.
Still another object is to provide a method of constructing and assembling hollow enclosures for coaxial cable devices which include a cylindrical body closed at one or both ends by a header wherein toque applied to the header does not result in relative rotation of the body and header.
Other objects will in part be obvious and will in part appear hereinafter.